Abstract
The prevalence rate of allergic disorders is increasing in industrial areas and countries. Recent reports suggest that some environmental pollutants are related to the increase in allergic diseases. Trichloroethylene (TCE) is widely used in many industries, and commonly detected as an environmental contaminant. TCE is known to have toxicity for the nervous system, liver, and kidneys, and also to show immunotoxicities like Th1 cells activation and inhibition of CD4 positive (CD4+) T cells apoptosis. We previously reported that TCE is a candidate chemical for causing the increase of allergic diseases, because TCE ingestion enhanced allergic reaction and antigen stimulated lymphocytes proliferation. However it has been unclear that TCE ingestion affects T cell responses. In the present study, we focused on the direct effect of TCE treatment on T cell proliferation in vitro.
The splenocyte and lymphocyte proliferation with T cell receptor (TCR) stimulation were significantly enhanced by TCE treatment. The enhancement of proliferative response was remarkable in CD8 positive (CD8+) cells. In addition, the phosphorylation of Lck in the CD8+ cells was also increased by TCE treatment. The ratio of CD8+ cells was also significantly increased by TCE ingestion with immunization. These result shows that TCE affects TCR stimulated cell proliferation and Lck phosphorylation that may cause the enhancement of sensitivity of CD8+ cells to antigen. In conclusion, TCE exposure enhances TCR-induced proliferation of CD8+ T cells to facilitate Lck phosphorylation and may cause disrupting in peripheral T cell activities.
